Average Car Battery Life and How to Extend It

As a car owner, one of the most frustrating things can be getting in your car on a cold morning, only to start the ignition and find that the car just won’t start. This is very likely due to a flat or dead battery, which can happen when you least expect it. 

What is the average life of a car battery?

The average life of a car battery can vary depending on several factors, such as the type of battery, the climate and weather conditions in which the vehicle is used, and the frequency of use.

Most car batteries tend to last around 3 to 5 years, but plenty of drivers have shared stories of theirs going strong for 8 or even 9 years with a bit of luck and good care. Some types, like Absorbent Glass Mat (AGM) batteries, are known to go the distance, with a few lasting over a decade.

It turns out your driving habits make a difference too. Short, stop-start trips can put more strain on your battery, but many drivers still find theirs holding up well even with city driving. Regular battery checks can help you avoid that sinking feeling when your car won’t start, and it’s still recommended swapping your battery after a few years, even if it seems fine, to avoid getting caught out unexpectedly.

How long do car batteries last in electric cars?

Electric car batteries are built to last much longer than the smaller 12-volt batteries you find in petrol or diesel cars. Most EV batteries are designed to last anywhere between 8 to 15 years, depending on how and where you drive.

EV manufacturers usually offer warranties on the battery for 8 years or around 100,000 miles, and many batteries continue to perform well beyond that, although you might see a gradual reduction in range over time. Of course, factors like frequent fast charging, extreme heat, and regularly running your battery very low can speed up battery wear, while gentle charging habits and moderate climates can help your EV battery last even longer.

How to extend car battery life

Fortunately, there are some ways you can prolong the life of your battery with these practical tips:

Protecting the car:

The lower the temperature outside, the worse it is for car batteries. The same applies for extremely hot weather where the heat can damage battery cells resulting in producing lower voltage. If possible, park your car in a garage or in a shaded area to protect it from extreme temperatures.

Drive your car regularly, especially in extreme climates:

Regular driving helps keep the battery charged and healthy. In colder temperatures, make sure to drive the car at least once a week for 20-30 mins to keep the battery recharged and healthy. 

Minimise use of power when engine is off:

Turn off all electrical accessories when you turn off the engine. This includes the radio, headlights, air conditioning, chargers, etc. that draw power from the battery. Leaving these on can drain the battery and shorten its life in the long run.

Check battery condition:

Have your battery checked regularly by a professional mechanic to make sure it’s holding a charge and functioning properly. If you’re familiar with car parts and electricals, you can use a multimeter to check battery voltage at least once a month. A healthy battery reading should be at least 12.6V. If it is slightly lower than this number, this does not necessarily mean it’s a bad battery but you may need to consider replacing it with a new one to avoid any issues in the future. 

Don’t leave it unused for extended periods:

Leaving a car unused for a long time can damage the battery. Remember, the battery relies on the alternator to recharge while the car is running which is why driving it regularly keeps the battery charged. If you know that you are going to leave your car unused for weeks or months, it’s advisable to use a battery trickle charger to keep the battery charged and in good condition. Some car owners, if leaving the car unused for months or years, also prefer completely removing the battery and storing it separately in a safe and controlled environment.

How to the check car battery life

There are two simple ways to check the life of your car battery:

1. Visual test: The first step is to check the battery for any signs of physical damage, such as leaks or cracks. If you notice any sort of corrosion or a green substance on the battery terminals then this can also be a sign of a problem. In some newer cars, the battery terminals are concealed with a covering and not easily visible. These require specialist equipment and it is best left to trained technicians. 
2. Voltage test: One of the easiest ways to check battery condition yourself is to do a test of the charge it’s holding. Use a multimeter (easily available at any hardware store) to test the voltage of the battery. There are also special testers known as ‘car battery testers’ available in the market. With the car turned off, connect the tester to the battery terminals – the red will go to the positive terminal and the black lead should be attached to the negative terminal.
   
   Remember, if you’re not confident, it’s always better to have a professional do this test as dealing with electricals can be dangerous if you are not familiar with it. A fully charged and healthy battery should read around 12.6 volts. If it reads anything lower than 12.4 volts, it may be time to recharge or replace the battery. 

Mechanics also carry out something called a ‘load test’ which is a diagnostic test to measure the ability of the battery to deliver the necessary power needed to start the car. Here, a special tool called a load tester is used to apply a controlled electrical load while also measuring the voltage. This is a more accurate and thorough test which can help understand the overall battery condition, and whether a new battery should be connected instead. 

How to preserve a car battery when not in use

If you are not going to be using your car for an extended period, such as a long trip abroad, it is important to take steps to preserve the car battery and prevent it from losing its charge. Here are some things you can do that could help: 

• Disconnect the negative terminal: If possible, disconnect the negative terminal of the battery to prevent any power drainage from the car’s electrical system. Known as parasitic or key-off battery drain, electrical devices such as radios, alarms, and computers continue to draw power from your car battery over time, draining the battery.
• Start the car every few weeks: If possible, start the car and let it run for a few minutes every few weeks which will help keep the battery charged. If you don’t have access to your car, you can always request a friend or relative to start the car once a month, if convenient.
• Consider removing it: If you won’t use the car for months, then you can consider removing the battery completely from the car. Be sure to store the battery in a safe and moisture-free environment. This will still mean the battery will drain naturally to some extent over time so may need to be recharged before you fit it back in.
• Keep the battery charged: If you don’t want to remove the battery from the car, then consider using a battery charger also known as a trickle charger to keep the battery charged while it is not in use. Be sure to check voltage specifications and follow the manufacturer’s instructions when using it as each brand has specific instructions you will need to follow.

When it comes to any DIY task involving your car battery (electrics!), the most important thing to remember is that if it’s outside your comfort zone or you’re even slightly unsure about something, call in the professionals. That’s exactly what they’re there for!

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